1. Field of the Invention
The present invention generally relates to a display and a driving circuit thereof, and more particularly to a flat panel display and a driving circuit thereof.
2. Description of the Related Art
Because of the advance of technology, electronic devices are widely used in our daily life, such as ATM, PC, cellular phone and TV. We can get information through the displays.
In recently years, the flat panel display (FPD) has gradually replaced the traditional cathode ray tube (CRT) display. The flat panel display (FPD) may be classified into a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting display (OLED), a field emission display (FED), etc. In almost all of the flat panel display FPD, a plurality of scanning (gate) signals is incorporated with a plurality of data (source) signals for generating images on the display. FIG. 1 illustrates an example of LCD.
FIG. 1A is a schematic circuit block diagram showing a driving circuit and a source driving circuit of a conventional LCD. The LCD 110 includes a plurality of gate terminals 113 and a plurality of source terminals 115. Each intersection of the gate terminals 113 and source terminals 115 has a pixel. The turn-on or turn-off of the pixel is dependent on the gate signals. The gate signal is generated from the gate driver 120 according to the scanning signal 147. The source signal is generated from the source driver 100. The source driver 100 receives a horizontal synchronous signal 143, the display data 145 and a plurality of gamma adjusting voltages 152 for generating the image driving signals.
FIG. 1B is a circuit block diagram of the source driver 100 of FIG. 1A, wherein only one set of channel driver 130 is shown. The gamma voltage generator 150 can receive a plurality of gamma adjusting voltages 152 for generating gamma voltages 151. The shift register 132 receives the display data 145 in serial for outputting the display data 133 in parallel. The line buffer 134 receives and latches the display data 133 for generating the display data 135 according to a timing of the horizontal synchronous signal 143. The D/A converter 136 receives the display data 135 and the gamma voltages 151 for outputting the image driving signal 137 by selecting one of the corresponding gamma voltages according to the display data 135. In order to enhance the driving ability of the image driving signals, a buffer 138 is connected to each output terminal of the source driver so that the buffer 138 receives the image driving signal 137 for outputting the image driving signal 139.
According to the conventional source driving circuit, the buffer 138 is provided for enhancing the driving ability of the signal (such as the current of the signal) without changing the signal characteristic (such as the voltage of the signal). In order to provide sufficient signal driving ability to the pixel, the conventional LCD 110 provides a buffer 138 at each source terminal. For example, if the LCD 110 has 400 source terminals, correspondingly 400buffers are required, and accordingly, the high power consumption thereof is substantially high.